Timber-framed building structures, and method of constructing same

ABSTRACT

A timber frame structure for a building, comprising elongate base members extending along lines of respective walls of the building, corner posts extending upwardly from the base members at intersections of respective walls, elongate head members extending between the corner posts at upper end parts thereof; and a plurality of wall panels extending between the head and base members to provide walls for the structure. The structure may be constructed by erecting a wall structure of a lower storey of the building, constructing a floor assembly, and assembling a roof truss assembly on top of the floor assembly, releasably connecting the roof truss assembly to the floor assembly using releasable connecting means, placing the connected floor and roof assembly on top of the wall structure of the lower storey, disconnecting the roof truss assembly from the floor assembly and removing the roof truss assembly from the floor assembly, constructing a wall structure of an upper storey on top of the floor assembly; and placing the roof truss assembly on top of the wall structure of the upper storey.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to GB Patent Application No. 0724035.1 filed Dec. 8, 2007 and GB Patent Application No. 0820795.3 filed Nov. 13, 2008, both of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

This invention relates to timber-framed building structures, to a method of constructing same, and to apparatus for use in such construction.

The timber-framed construction is well known for use in relatively small buildings such as houses, offices, hotels and others, and has many advantages when compared with traditional constructional techniques wherein the load-supporting walls of a building are constructed of bricks and/or blocks. One such advantage is speedy construction and another such advantage is that a timber-framed house can be highly energy efficient compared with one of traditional construction. Timber itself has good thermal insulation properties, and a wall constructed of timber-based materials, with suitable insulating materials, can be highly insulative. Indeed, future requirements for effectiveness of insulation in houses will mean that timber-framed construction becomes much more widely used, to the extent that virtually all newly-built houses will need to be of this type if they are to comply with the applicable regulations. At the same time, timber-framed walls have adequate stability and strength to support the weight of the floors and roof of small buildings as aforesaid, of up to about six storeys, and, when suitably treated and finished using materials such as plasterboard, have sufficient durability including resistance to damage by fire.

In general, timber-framed houses hitherto have taken the design of traditionally-constructed buildings as a starting point, the timber framework being designed and the necessary structural calculations carried out to suit the shape and dimensions of the required building. Components of the timber structure are then factory-made to the required dimensions, and prefabricated into structural sub-assemblies which can be transported to a construction site and erected to form the building. On site, a foundation, for example a concrete raft, is constructed at the required position, and scaffolding erected to enable the timber framework then the rest of the building to be constructed.

Whilst such construction methods enable buildings to be erected quickly compared with traditional constructional techniques (the erection of the timber framework for a timber-framed house might only take a few days) there are disadvantages. One is that from the design and structural engineering viewpoint all the buildings are to some extent individual, so that although some common components can be utilized, the extent to which this can be achieved is limited. For each variation in size and design of a house, new structural calculations have to be performed and components manufactured to suit the relevant dimensions. It would be desirable if more use could be made of common components, and the need for individual calculations reduced or eliminated, when designing different buildings.

On site, once a foundation has been established, the scaffolding has had to remain in situ not only during the erection of the basic timber framework of the building but during all subsequent building stages including the construction of cladding walls (which may be traditionally built of masonry, i.e. bricks/blocks), roofing, and the installation of high-level external fittings such as guttering and downpipes. Indeed, the scaffolding will have to be reconfigured between the erection of the timber-framed structure and the construction of cladding walls, being disposed further away from the timber-framed structure for the latter operations. Further, fall-arrest systems such as special-purpose airbags have to be provided inside the timber framed structure, until such time as internal floors have been installed. These requirements are expensive.

SUMMARY OF THE INVENTION

It is broadly the object of the present invention to address one or more of the above mentioned disadvantages of previously-known timber-framed structures for buildings such as houses. The manner in which the present invention, in its various aspects, deals with this will be described in greater detail hereafter.

According to one aspect of the invention, I provide a timber frame structure for a building, comprising:

elongate base members extending along the lines of respective walls of the building;

corner posts extending upwardly from the base members at intersections of the respective walls;

elongate head members extending between the corner posts at upper end parts thereof, above the base members; and

a plurality of wall panels extending between the head and base members to provide walls for the structure.

The wall panels may comprise selected ones from a number of standard panels, which can be placed in relation to one another to provide a length of wall corresponding to each distance between the corner posts.

At least some of the wall panels may be able to overlap one another in the direction lengthwise of the head and base members, to accommodate changes in the distance between the upwardly extending edges of the panels which are remote from one another.

Each wall panel may comprise spaced elements of timber which are upright in use, extending between the head and base members, and a board material connected to the upright elements on one side thereof to provide a wall surface between the head and base members. Preferably the board material of each panel has upper and lower edge portions which extend to cover (at least partially) corresponding side surfaces of the head and base members respectively, and are secured to the head and base members to fix the panel in position.

To provide for the adjustment of the position of adjacent wall panels relative to one another in the direction lengthwise of the head and base members, a panel may include a board portion which extends beyond an upright element at an upright edge of the panel, so that it can overlap with the upright edge of the board portion of an adjacent panel, which is disposed to the opposite side of the head and base members to the board material of the first-mentioned panel.

Each head member may comprise an I-beam, with timber chords and a web, oriented with its chords spaced vertically above one another and its web extending substantially vertically therebetween.

The lower chord of such a head member may be arranged to form a lintel where door or window openings are to be provided in the wall. The corner posts may have portions arranged to support the lower chord of the I-beam at a suitable height for this purpose.

Each head member may comprise two of the I-beams disposed one on top the other in the same orientation as one another. The upper I-beam may provide support for an elongate base member and corner posts to form another storey above the first-erected storey of the building, and for joists for a floor of the upper storey.

Each wall panel may comprise an insulation material, preferably provided on a side of the board material to lie between the upright elements of the panel. Such an insulation material may comprise, for example, an expanded polyurethane type of material, of a suitable thickness, e.g. 100 mm or greater for higher insulating qualities. A vapor barrier, e.g. a membrane of sheet plastics material, would also be incorporated where the wall panel is for an exterior wall of a building. Where adjustment of the position of adjacent panels is required, the insulation material would be removed as necessary from the board material which is required to extend beyond the edge of the adjacent panel.

In a building structure in accordance with the invention, the corner posts and head members may be dimensioned such that a predetermined maximum span of e.g. 10 metres between adjacent corner posts is acceptable. For any smaller span, the head member may be stronger than is necessary, but this is not disadvantageous since it enables a head member of cross-sectional shape and dimensions suitable for the 10 metre span to be used for all spans up to that limit. If the length of a wall between respective walls extending in different directions exceeds the limit, the same cross-sectional dimensions of head member could still be utilized but an additional upright member, analogous to a corner post, would have to be utilized between the ends of the wall to support a first head member and a further one of the required additional length. If the internal space of the building is divided by an internal wall, the additional upright member would be disposed where the internal wall is required to join the external wall. Any internal walls required in the building would be of analogous construction to the external walls utilizing head and base members, and wall panels providing for length adjustment in the direction lengthwise of the internal wall, in the same manner as the panels for external walls.

The head members for a lower storey of the building, which carry the base members for a superposed storey, may be connected together to form a ceiling and floor sub-assembly for the lower and upper storeys respectively, which sub-assembly can be constructed away from the building structure and placed in situ as a unit. Similarly, at the top of the highest storey in a building, head members each comprising a single I-beam may be assembled together with a timber roof structure to form a ceiling and roof sub-assembly which can be fitted as a unit. Such sub-assemblies may be placed in position on a building by use of a crane.

The invention also provides a method of constructing a timber frame structure for a building, utilizing elements of the first aspect of the invention as above described.

In order to create a building structure in accordance with the invention, the first step, performed on site, would be to install a foundation, for example a concrete raft, of the required overall size of the building. Base members for the external and any required internal walls of the building would then be placed in position on the foundation, and corner posts and any necessary additional upright member positioned at the intersections of the respective external, and any internal, walls. They would be secured to the base members, and supported in the required upright orientation.

Head members, preferably of the configuration above set forth each comprising two I-beams disposed one above the other, would then be assembled to one another in the required positions to form a sub-assembly of the head members for all the walls of the building. Such assembly would not be carried out in situ, but rather at a convenient location near the positioned upright members, e.g. on the ground nearby. This sub-assembly is preferably also provided with joist members to provide flooring for the next storey of the building. Preferably the joists are boarded with floor boards. The entire sub-assembly of head members, joists and floor boarding can then be moved by crane to be positioned as required on the corner posts.

After the sub-assembly of head members, joists and floor boarding has been positioned, the panels forming the walls of the structure can be fitted between the head and base members. Each panel is fitted individually, with appropriate use of panels which can overlap one another as aforesaid in the case where the length of a wall does not permit the use of panels disposed end to end with one another.

Prior to being lifted into position, the sub-assembly of head members and joists for the ceiling structure of the lower storey and floor structure of the upper one may be provided with a guard structure, e.g. hand rails so that construction personnel can work on the erection of the structure for the upper storey from the floor structure thereof without requiring any external scaffolding or other safety systems. The hand rails or other guard structure may be secured to the respective head members, to remain in position until their removal is necessitated by the construction of external walls, e.g. of brick outside the timber-framed structure.

Internally of the timber-framed structure, plasterboard would be fitted to the inside surface of the timber frame panels, and to the ceiling beneath the joists of the assembly of head members.

The construction of the next storey of the building would then be commenced by the positioning of corner posts at the intersections between respective external and internal walls of that storey, such corner posts being secured and supported in the upright position relative to the base members fitted to the sub-assembly of head members at the top of the lowermost storey. A sub-assembly of head members for the upper storey would, if this is the uppermost storey, be constructed with a roof truss structure which can be moved into place by a crane. The fitting of wall panels to the walls of this upper storey can, on the inside of the timber framed structure, be carried out from the floor which has been fitted with the head members to the tops of the corner posts of the lower storey, while panels fitted in the exterior of the timber framed construction can be fitted from the scaffolding erected as aforesaid. Plasterboard to provide the finish of the walls of the upper storey, and for the ceiling thereof, can be fitted to the timber framed structure and to the roof truss structure by standing on the floor of the upper storey, i.e. no scaffolding nor fall-protection systems are required in the interior of the building.

Thus far, if hand rails have been utilized as aforesaid, the erection of the structure has been carried out without requiring the use of scaffolding. Suitable scaffolding would then be erected around the timber-framed structure to enable external walls of bricks, for example, to be built up outside the timber framed structure.

The scaffolding would be raised in height as necessary as the construction of the external walls proceeds.

A preferred method for constructing a timber-framed building includes the steps of:

erecting a wall structure of a lower storey of the building; constructing a floor assembly, and assembling a roof truss assembly on top of the floor assembly; releasably connecting the roof truss assembly to the floor assembly using releasable connecting means; placing the connected floor and roof assembly on top of the wall structure of the lower storey; disconnecting the roof truss assembly from the floor assembly and removing the roof truss assembly from the floor assembly; constructing a wall structure of an upper storey on top of the floor assembly; and placing the roof truss assembly on top of the wall structure of the upper storey.

The method may further include constructing the floor assembly and roof truss assembly at ground level, adjacent the wall structure of the lower storey of the building.

Preferably the releasable connecting means comprises a number of connecting assemblies, each comprising a connecting member and a receiving member with which the connecting member is releasably engageable; the connecting member being provided on one of the roof truss assembly and the floor assembly and the receiving member on the other thereof, the connecting member and receiving member engaging and disengaging with one another by relative vertical movement between the roof truss assembly and the floor assembly.

Preferably the method further includes providing a guard structure on a part of the releasable connecting means engaging the floor assembly. The method may include displacing the guard structure relative to the connecting assemblies of the releasable connecting means, between a first position in which the guard structure is positioned relative to the or each connecting assembly so as to enable the roof structure to be connected and disconnected from the floor assembly, and a second position in which it is effective to guard against falls from the upper storey. Displacing the guard structure relative to the or each connecting assembly may comprise pivoting the guard structure between the first position and second position.

The method may include storing the materials for use in the construction of the wall structure of the upper storey on the floor assembly prior to assembling the roof truss structure on top of the floor assembly, so that when the roof truss structure is disconnected from the floor assembly, the materials are disposed on the upper storey for use in the construction of the wall structure.

The method may further include providing a plurality of spaced parallel joist members between opposite beams of the upper beam assembly, and laying a floor over the joists, during the construction of the floor assembly.

According to a further aspect of the invention, I provide a releasable connecting means for connecting a roof truss assembly to a floor assembly, including a number of connecting assemblies, each of which comprises a connecting member and a receiving member, each connectable to the roof truss assembly and floor assembly respectively.

The receiving member may have an opening within it, with which at least a part of the connection member is engageable, and the or each connecting assembly further includes a fastening means for holding the connection member in engagement with the receiving member.

The releasable connecting means may further include a guard structure which is provided on a part of the releasable connecting means engaging the floor assembly. The guard structure may include two legs, each leg being connected to a respective receiving member. The guard structure may be displaceable relative to the connecting assemblies, between a first position in which the guard structure is positioned relative to the or each connecting assembly so as to enable the roof structure to be connected and disconnected from the floor assembly, and a second position in which it is effective to guard against falls from the upper storey. Displacing the guard structure relative to the or each connecting assembly may comprise pivoting the guard structure between the first position and second position. The guard structure may be a handrail assembly which may be extendable lengthwise (e.g. telescopically).

According to yet a further aspect of the invention, I provide a roof truss assembly disposed on top of a floor assembly, releasably connected to one another by releasable connection means according to the second aspect of the invention.

The use of a timber frame structure according to the invention, as above described, enables a timber-framed building to be erected extremely rapidly compared with timber-framed building structures and techniques known hitherto. For example, it is estimated that the entire timber frame structure for a relatively small building, e.g. a house with a floor area of about 1000 sq ft, could be erected in a single working day. Since the timber frame structure can be erected as above-described without the use of scaffolding, the time for which scaffolding has to be on site and erected is substantially reduced. Also, there is no requirement for dismantling or partial dismantling of erected scaffolding and re-erecting thereof in a different configuration between the stages of building the timber frame structure and building external walls of brick. Scaffolding might be required to be in use for only, approximately, half the length of time it has been necessary for previously-known timber-framed constructional techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example only with reference to the accompanying drawings, of which:

FIG. 1 is a perspective view of an embodiment of timber framed structure, in accordance with the invention;

FIG. 2 is a perspective view of elements of the lower storey of the structure;

FIG. 3 is a perspective view of a corner post of the structure;

FIGS. 4, 5 and 6 are perspective views of wall panels for use in the structure;

FIGS. 7, 8 and 9 are perspective views illustrating the disposition of wall panels in relation to one another in a structure;

FIGS. 10 and 11 are perspective views and elements and assemblies of the building structure in accordance with the invention.

FIG. 12 is a front view of receiving members and attached guard structure shown in connection with a timber-framed building construction;

FIG. 13 is a perspective view of a releasable connecting means shown in connection with a floor/roof assembly;

FIG. 14 is a perspective view of a first storey of a building construction having an attached floor assembly, with attached receiving members and guard structures, and a roof truss assembly having attached connecting members.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring firstly to FIGS. 1 and 2 of the drawings, this shows a timber-framed building structure in accordance with the invention. The structure is for a building (e.g. a house) having two storeys, namely a lower storey 10 and an upper storey 12, surmounted by a pitched roof structure 14. Corner posts for the lower storey 10 are visible at 16, 18 respectively, and for the upper storey at 20, 22. A head member for the visible wall of the lower storey 10 is indicated at 24, which is incorporated as described hereafter in an assembly which also forms the floor of the upper storey 12. A head member for the visible wall of the upper storey is indicated generally at 26, and this head member supports the roof structure 14. The entire structure is constructed on a foundation 30 such as a concrete raft, and on this foundation are supported elongate base members upon which the walls of the structure are carried and accordingly which extend along the lines of such walls. Two adjacent such base members, meeting at the corner post 16, are visible at 32, 34 respectively.

FIG. 2 of the drawings shows one of the corner posts 16 or 18 of the lower storey 10. The corner post 16 is shown in greater detail in FIG. 3. It comprises two generally U-shaped members 36, 38 disposed at right angles to one another, the member 36 comprising two spaced parallel upright timber elements 40, 42 joined by a board element 44, e.g. of plywood, which extends above the upper ends of the members 40, 42 and a small distance below the lower ends thereof. Similarly the member 38 comprises timber elements 46, 48 and a board element 50, e.g. of plywood connecting the timber elements 46, 48 and also extending above the level of the upper ends of such elements and a small distance below the level of the lower ends of such elements. Further timber members 52, 54 are disposed to occupy the right-angled corner between the members 42, 46, and suitable fastening elements secure these components together as illustrated.

In FIG. 2, it will be seen that the bottom ends of the timber members 40, 42 rest on the base member 34, and the bottom ends of the timber members 46, 48 likewise rest on the base member 32. The lowermost edges of the board elements extend down to the top surface of the foundation 30.

The tops of the corner posts at the intersections of the walls of the building are joined by respective head members. As seen in FIG. 1, the tops of the corner posts 16, 18 are joined by a head member comprising an I-beam 60 above which is a further I-beam 62. The lower I-beam 60 is seen in isolation in FIG. 7 of the drawings, and it will be noted that it comprises upper and lower chords 64, 66 extending parallel to one another and secured together in such relationship by an upright web 68 extending there between. The upper I-beam 62 is of the same configuration, its lower chord being connected to the upper chord 64 of the I-beam 60. The assembly of I-beams 60, 62 is used in providing an assembly which forms the basis for the ceiling of the room or rooms forming the lower storey 10 and the floor for the upper storey 12. The lower I-beam 60 is supported on the uppermost ends of the upright members 40, 42, 46, 48 and 52, 54, of each of the corner posts.

The timber frame structure further comprises wall panels which fit between the base member and head member of each respective wall of the structure. In FIG. 1 the visible wall of the lower storey of the building has a number of wall panels indicated at 70, 72, 74, 76, 78, 80 and 82. These panels are selected ones of a number of standard panels.

Firstly, the panels 70, 72, 74, 76 and 78 are each as shown in FIG. 6. This comprises a board 90 of plywood, to which are secured three spaced parallel upright timber stud elements 92, 94, 96. The board 90 extends above the level of the stud elements and below the bottoms thereof, in the same manner as the board elements 44, 50 of the corner post shown in FIG. 3. A further type of wall panel is shown in FIG. 5, which comprises a board element 98 and two stud elements 100, 102. This panel, used as the panel 82 in the wall shown in FIG. 1, is as the panel of FIG. 6 but of only half the width thereof.

Yet a further panel is shown in FIG. 4. This is as the panel of FIG. 6, having a board member 104 of the same dimensions but with only two stud elements 106, 108 of which the later is disposed centrally of the board member and the former at one edge. The stud element 106 could be disposed at the opposite edge of the board member 104 so as effectively to make a left-handed or a right-handed panel according to the edge at which it is disposed. A panel with the stud element 106 at the opposite edge to that where it is shown in FIG. 4 is used as the panel 76 in the wall visible in FIG. 1.

Finally, the panel 80 in FIG. 1 is as the panel 6 but is cut off at a suitable height above its lowermost end to provide an opening above it for installation of a window.

Although not shown in the illustration, each of the panels above described would also incorporate thermal insulation, e.g. of plastics material such as polyurethane foam, occupying the space between the stud elements of the panel. A vapor barrier, e.g. a plastics membrane, would also be included so that the wall has, in addition to the required thermal insulation, appropriate resistance to passage of water vapor across the wall.

FIGS. 7, 8 and 9 illustrate the manner in which, in the erected timber frame structure, the wall panels as above described fit in relation to the base and head members 34 to form the walls. FIG. 7 shows a panel as shown in FIG. 6, with its stud elements 92, 94, 96 extending between the base member 34 and the lowermost chord of head member 60. The board 90 of the panel, where it extends below the lower ends of the stud elements, lies against the side face of the base member 34 while where the board extends above the upper ends of the stud elements it lies against the side of the lower chord 66 and up to the upper chord 64.

FIG. 7 shows another panel which is of a type shown in FIG. 4, arranged with its board 104 on the opposite side of the base member and the head member to the board 90 of the first panel. Because there is no stud element at the visible upright edge of the board 104, the board 104 is able to overlap the first panel in the direction lengthwise of the base element and head member, up to the point at which the stud element midway between the upright edges of the panel abuts the stud element 96 of the first panel, thereby allowing some adjustment in the total distance between the upright edges of the two illustrated panel.

Referring now to FIGS. 8 and 9 of the drawings, these show diagrammatically, a base member 34, a head member 60, a panel as shown in FIG. 6 whose board is illustrated at 90, and a panel as shown in FIG. 4 (but of opposite hand) whose board is indicated at 104 and stud elements at 106, 108. In FIG. 9, the panel 104, 106, 108 has been slid towards the first panel until it overlaps therewith to virtually the full extent of the board 104 which extends beyond the stud element 108. To enable this to be done, of course, an appropriate amount of insulation has to be removed from the board 104 (although it will be appreciated that no insulation is shown in these figures in any event).

In FIG. 1, a space is shown between panels 76, 78. This space may be dimensioned to fit the fixed peripheral frame of a door. Suitable adjustment between the relative positions of panels 74, 76, in the manner shown in FIGS. 8 and 9, enables the space between the panels 76, 78 to be adjusted to match the width of the door frame.

Hence, whatever is the length of a wall of a timber frame structure, and whatever windows and doors might be included in it, it can be constructed by using a small number of “standard” panels. The head member extends between corner posts at the end of the wall, and provides the lintel above each door and window opening.

Internally of the building, the walls would be finished by the application thereto of plasterboard sheets which can then be plastered, as is done for known timber-framed building structures. Where, on the interior surface of the timber-framed structure, one or more stud elements of wall panels are presented without a covering board, a timber filling element of thickness corresponding to the ply-wood boards of the wall panels has to be secured to each stud element so as to present a surface co-planar with the surface of the ply-wood boards to which the plasterboard can be fixed.

The dimensions of a head member 60, 62 are selected so as to provide adequate structural strength for a wall up to a predetermined length, e.g. 10 metres between corner posts. If a building has a wall longer than this, an additional supporting post or posts may be provided between the corner posts at the ends of the wall, and an additional head member or members of suitable length used. Where a building has one or more structural internal walls, a supporting post analogous to a corner post would be provided where an internal structural wall intersects the external wall of the structure.

Referring now to FIG. 10 of the drawings, this shows the lower storey of the timber frame structure, with one wall thereof being seen in detail with a head member comprising two I-beams 120, 122 supported on the ends of the upright members of corner posts at the ends of the wall, and with wall panels in position to provide the timber wall structure with suitable openings for a window and a door. As above described, the lower I-beam 120 of the head member forms the lintels above the doors and window openings. The upper I-beams on opposite sides of the structure have a plurality of spaced parallel joist members as indicated at 124 extending between them to provide a support for floor boarding for the upper storey of the building and to provide for attachment of plasterboard to form a ceiling of the lower storey. The joists 124 may be secured to the opposite I-beams by conventional joist hangers.

FIG. 10 also shows that the upper I-beam 122 has secured to the upwardly-facing surface of its upper chord a timber member 126 which forms a base member for the support of corner posts for the upper storey of the structure and for panels to form the wall of that structure. The panels used for the upper storey are the same as for those used for the lower storey, and they are assembled in the same manner as for the lower storey in relation to the base members, corner posts, and head members to form the upper storey. Further storeys of the same configuration could be provided, up to, perhaps, six storeys.

FIG. 11 shows a roof truss assembly for the structure. It includes two I-beams 130, 132 which form the head members extending between respective corner posts on opposite sides of the structure. These I-beams are identical to the I-beams 60, 62 and the other I-beams used in the head members of the structure. The beams 130, 132 are joined by a number of spaced parallel joists 134 whose ends are secured to the upper chords of the respective I-beams. The roof structure further comprises rafters 136 and upright and inclined braces 138, 140, all arranged in known manner for such roof structures. In installation of the roof structure, as a final or near-final stage of the erection of the timber frame structure as above described, the structure shown in FIG. 11 would be constructed on site at ground level from the respective components as above described. The head members in the form of I-beams 130, 132 for the one pair of opposite walls of the building structure would be assembled with the roof as shown in FIG. 11, while the head members of the other pair of opposite walls of the structure would be fitted to the tops of the respective corner posts.

The complete roof assembly, as shown in FIG. 11, would then be lifted by crane to be fitted on top of the previously-erected roofless structure.

To construct a timber-framed building structure in accordance with the invention, the first stage to be conducted on site is the preparation of a foundation, e.g. a concrete raft, upon which the base members for the walls of the lower storey would be installed. The corner posts would be connected to the base members where the external walls (and any internal walls) meet, and temporarily supported in an upright orientation.

A structure forming the head members to be supported on the corner posts of the lower storey would be constructed on site at ground level, including the joists which carry the floor of the upper storey and ceiling of the lower storey, and lifted by crane to be positioned as shown in FIG. 10, this structure including the base members for the walls of the upper storey. It is then possible to install the panels forming the walls of the lower storey, extending between the base members and head members thereof. Construction of the upper storey including its corner posts, roof structure as above described, and finally panels forming the walls of the upper storey can then be undertaken.

A preferred method of construction will be described with reference to FIGS. 12-14 of the drawings.

Referring now to FIG. 12, this shows a timber-framed building structure 210, which is of the type described in detail above and therefore will be described only briefly hereafter. The structure comprises a lower storey 214 and an upper storey 216, on top of which is disposed a roof truss assembly 218.

The lower storey 214 is constructed on a foundation 212 such as a concrete raft. Elongate base members are disposed on top of the foundation 212, extending along the lines of the walls of the structure and upon which the walls of the structure are carried. Corner posts 226 are located at junctions of base members, providing a support between the base members and a lower beam assembly 220, comprising wooden beams with an I-shaped cross-section, which lies generally parallel to the base members along the lines of the walls.

A wall structure is erected on the base members and extends up to the lower beam assembly 220, the wall structure including panels 228 formed from boards of plywood, which are secured to spaced upright timber elements. Panels 228 may be cut off at a suitable height to provide an opening for installation of a window, and a space may be left between panels 228 to allow for installation of a doorframe. The lower beam assembly 220 forms the lintels above doors and window openings.

The upper storey 216 includes a floor structure at its base which includes an upper beam assembly 222 which is connected to and lies above the lower beam assembly 220 of the lower storey 214. The beams comprising the upper beam assembly 222 on opposite sides of the structure have a plurality of spaced parallel joist members 230 extending between them (which may be connected by conventional joist-hangers) which provide a support for the floor of the upper storey 216, and to provide a surface onto which plasterboard may be attached to form a ceiling of the lower storey.

Base members are positioned on the upper beam assembly 222 to form a base for the wall structure of the upper storey 216, in a similar way to the base members disposed on the foundation 212 for the lower storey 214. A wall structure is erected in the same manner as for the lower storey 214, in relation to the base members, corner posts 236, and beams 224 which form part of the roof truss assembly 218, to form the upper storey 216.

The roof truss assembly 218 includes two beams lying parallel one another which extend between respective corner posts 236 of the upper storey of the structure. The beams 224 are joined by a plurality of joists 246 which are secured to the top surface of the beams, running parallel one another between the two beams. Rafters 240 extend upwards from either side of the structure, spaced from one another along the length of the beams 224 so as to align with the joists 246, held in connection with the joists 246 on either side of the structure, and defining a ridge 248 over the centre of the roof truss assembly 218. The lower ends 240 a of the rafters 240 overhang the beams 224 downwardly and outwardly so as to form the eves of the roof structure. The roof truss assembly 218 further includes upright braces 242 and inclined braces 244, arranged in a known manner for such roof structures.

Releasable connecting means 260 are used to secure the lower 220 and upper 222 beam assemblies to the roof truss assembly 218 during construction. The releasable connecting means 260 includes a number of connecting assemblies, each comprising a receiving member 252 and a connecting member 224. Each receiving member is connected to a guard structure, which is a handrail in this case, and shall hereafter be referred to as a handrail assembly.

Each receiving member 252 is generally box-shaped, having a flat rectangular front face 274 upon which brackets 270 are provided, holding a pin to provide a pivotable connection between the respective receiving member 252 and a respective first end 272 a of a leg 272 of a handrail assembly 250. The receiving member 252 has an aperture inset from each corner of its face, so that the receiving member 252 can be attached to the connected upper 222 and lower 220 beam assemblies by way of fastening means (such as bolts). A further aperture 268 is disposed towards the bottom of the face 274 of the receiving member 252, and extends through the receiving member to allow insertion of a bolt.

For each receiving member 252 there is provided a connecting member 254, which is a generally rectangular plate, having a first aperture 264, a second aperture 262 and a third aperture 258 provided centrally across its width and spaced along its length, the first aperture 264 being in close proximity to a first end 254 a of the connecting member 254 and the third aperture 258 being in close proximity to a second end 254 b. The connecting member 254 is attached to one of the beams 224 of the roof truss assembly 218 by way of a bolt which is inserted through the second (central) aperture 262 of the connecting member 254. When in connection with a beam 224 of the roof truss 218, the first end 254 a of the connecting member 254 protrudes above the truss, so that the aperture 264 is unblocked by the beam.

Each receiving member 252 further includes an opening 276 extending downwardly through it from an elongate slot in its upper surface, for receiving the second end 254 b of a connecting member 254. The location of the aperture 268 in the face of the receiving member 252 is such that when the connecting member 254 has been inserted to its full extent, the aperture 268 in the receiving member 252 aligns with the third aperture 258 in the connecting member so as to receive fastening means in the form of a bolt to hold the receiving member 252 relative to the connecting member 254.

The handrail assembly 250 includes a pair of legs 272, a first end 272 a of each of which is pivotably connected to the respective front face 274 of a receiving member 252, by the brackets 270 and pin held thereby. The second end 272 b of each leg 272 is connected to the upper rail 268 a of a pair of elongate rails 268, which extend parallel one another in a direction transverse to the alignment of the legs 272 so as to be in parallel alignment with the surface of the beams 220, 222 to which the receiving members 252 are connected. The elongate rails 268 are hollow, and inside each is connected a generally C-shaped end rail 266. Each end rail 266 has a smaller cross-section than the elongate rails 268, and has two elongate portions 265 which extend parallel to one another and perpendicular to a straight back section 267. The elongate portions 265 of the end rails engage with the hollow elongate rails 268, such that they are slidably connected to the elongate rails 268, allowing the rail to be extended at both ends. To prevent the end rails 266 from disconnecting from the elongate rails 268, stop formations are provided.

The handrail assembly 250 is pivotably moveable between a first position, in which the legs 272 of the handrail assembly define an angle of roughly sixty degrees with the plane of the surface of the beams 220, 222 to which the receiving members 252 are connected, and a second position wherein the legs 272 are in an upright orientation.

To provide for the pivotal movement of the handrail assembly 250, an aperture is provided adjacent the first end 272 a of each leg 272 of the handrail assembly 250, extending across its width, the aperture being elongated in the direction lengthwise of the leg 272, and engaged by the pin held by the brackets 270 on the face of the receiving member 252. As the handrail assembly 250 is moved from the first position to reach the second position, the first end 272 a of each leg is allowed to drop, as the leg is allowed to move downward relative to the position of the pin within the aperture. The leg 272 can move no further downward once the pin meets the top of the aperture in the leg, and as the wall of the leg 272 lies adjacent the face 274 of the receiving member 252, the handrail assembly 250 cannot pivot about the pin. In order to release the handrail assembly 250 so that it can be moved back to its first position, the legs 272 must be lifted so that the pin lies against the lower end of the elongate aperture, so that the wall of the leg no longer lies adjacent the face 274 of the receiving member 252. It is then possible to move the leg 272 pivotably back to the first position.

A timber frame building 210 as shown in FIG. 12 may be constructed by the method described hereafter, which involves a substantially reduced use of scaffolding, compared with previously-known construction methods, and requires land not much greater in size than twice the footprint of the building itself.

First, as described above, a concrete raft or other foundation 212 is laid on the site where the building is to be erected. Base members for the lower storey 214 are laid on top of this foundation 212, extending along the lines of the external walls between the corners of the building. Corner posts 226 are erected where the base members meet one another. A wall structure is erected along the lines of the base members by connecting panels 228 to the base members and holding them in an upright position using temporary braces.

Once the lower storey 214 of the building has been constructed, the beams and other components used in the construction of the upper storey 216 of the building, and the roof truss assembly 218, are assembled on the ground next to the partly constructed building. This assembly of beams and roof truss assembly 218 shall be referred to as the connected floor and roof assembly.

The connected floor and roof assembly includes the lower beam assembly 220, which is an arrangement of beams matching the layout of the base members laid on the foundations 212 of the building, so that each beam has the same length and relative position as a corresponding base member of the lower storey 214. The beams are connected to one another so that they form an outline of the perimeter of the building structure.

On top of the lower beam assembly 220 lies an upper beam assembly 222, each beam in the upper beam assembly 222 having a corresponding beam in the lower beam assembly 220 (in terms of length) to which it is secured, so that the upper beam assembly 222 matches the lower beam assembly 220 and is connected to it so as to lie directly above it, forming what shall be referred to as the floor assembly. A plurality of spaced parallel joist members 230 is connected between opposite upper beams, which provides a support for the floor surface of the upper storey 216.

Flooring boards or panels are now laid over the joist members 230. A cover is placed over the stair well, i.e. the opening where the stairway of the building will open onto the floor of the upper storey, so the floor is uninterrupted. The arrangement of connected upper 222 and lower 220 beam assemblies, complete with its flooring, shall be referred to as the floor assembly. Once the floor has been laid, the panels 238 which will make up the wall structure of the upper storey are laid over the flooring, so that they will be available when it is necessary for them to be fitted.

A roof truss assembly 218 is constructed on top of the floor assembly, as hereinbefore described, so that the two main beams 224 of the roof truss assembly 218 are disposed above the equivalent beams of the upper beam structure 222, to align the length of the roof with the wall structure running the length of the building structure as required. The roof truss assembly 218 further includes rafters 240, joists 246 and support braces 242, 244 as described above.

Pairs of connecting assemblies are used to secure the floor structure and roof truss assembly 218 to one another. Each connecting assembly includes a connecting member 254, which is attached to a beam 224 of the roof truss assembly 218 by the insertion of a bolt through the second aperture 262 and into a corresponding aperture in the beam. Pairs of connecting members 254 are spaced from one another so that they align with pairs of receiving members 252.

The receiving member 252 of each connecting assembly is attached to the upper 222 and lower 220 beam assemblies by way of bolts, so that the front face 274 of the receiving member 252 faces outwards from the upper 222 and lower 220 beam assemblies. The second end 254 b of each connecting member 254 engages with the opening 276 extending from the upper surface of the corresponding receiving member 252 of the connecting assembly, so that the aperture 268 in each receiving member 252 aligns with the third aperture 258 of the connecting member 254. A fastening means is inserted through the apertures in order to hold the connecting members 254 in engagement with the receiving members 252, and in doing so, hold the beam 224 of the roof truss structure in attachment to the underlying upper 222 and lower 220 beam assemblies.

Once the floor and roof assembly has been connected using the connecting assemblies, the first aperture 264 in each connecting member 254 protrudes between the rafters 240 of the roof truss assembly 218, allowing it to be connected to a hook of a crane 256. Each of the connecting members 254 at each side and possibly end of the structure is connected to the crane hooks in this way, allowing the crane to lift the connecting members 254, and in doing so lift the entire floor and roof assembly.

The crane positions the floor and roof assembly over the lower storey 214 of the building which has been erected, and lowers the floor and roof assembly onto the walls which are supported by braces. Whilst being held in place by the crane, the lower beam assembly 220 can be connected to the corner posts 226 of the lower storey, and the panels 228 of the lower storey wall structure can then be secured to the lower beam 220 so that the braces supporting the wall structure on the lower storey can be removed.

Having connected the floor and roof assembly to the lower storey 214 of the building, workmen are able to walk on the upper storey 216 due to the fact that the upper storey floor has already been laid out on the joists 230 connected to the upper beam assembly 222.

The bolts connecting the receiving member 252 and the connecting member 254 of each connecting assembly can be removed by being pulled inwards by workmen on the upper storey 216. This means that the roof truss assembly 218 is no longer attached to the upper 222 and lower 220 beam assemblies.

The crane lifts the roof truss assembly 218 from the top of the construction, allowing the workmen to work on the upper storey 216.

In order to meet safety requirements concerning the provision of fall prevention apparatus to allow the workmen to safely work on the upper storey 216, the handrail assemblies 250 must be moved into their second (i.e. upright) positions. This can be achieved from ground level outside the building, by using a rod of sufficient length to push the handrail assemblies 250 so that they stand upright. Once the handrail assemblies 250 reach an upright position, they are able to drop downwardly owing to the elongate configuration of the apertures in the legs, through which the pins extend.

The end rails 266 at either end of each handrail assembly 250 may then be extended so as to provide a barrier along the edges of the upper storey 216 where the receiving members 252 are connected. This enables the workmen to arrange the panels 238 and corner posts 236 on the upper storey, as the panels 238 and corner posts 236 themselves were stored on the upper beam assembly 222 once the floor was laid prior to being lifted into position on the building structure, so there is no need for any of the parts to be lifted to the upper storey 216.

The wall structure on the upper storey 216 is erected in the same manner as that on the lower storey 214.

Once the wall structure is in place on the upper storey 216, and has been secured by braces so as to hold it in position, the crane moves the roof truss assembly 218 back into position above the upper storey 216. The beams 224 of the roof truss assembly 218 can be secured to and supported by the corner posts 236, allowing the wall structure to be secured to the beams 224, and the braces to be removed.

With the roof truss assembly 218 in place and secured to the rest of the construction, the bolts holding the connecting members 254 (through their second apertures 262) to the beams 224 in the roof truss assembly 218, are pulled inward, releasing the connecting members 254 from the roof truss assembly 218. The connecting members 254 remain attached to the hook of the crane by way of their first apertures 264, and may be lifted away from the sides of the building.

Once the construction on the upper storey 216 has been completed, all that remains is to remove the receiving members 252 and the attached handrail assemblies 250 from the sides of the building. To do this, workmen can stand on a step placed against the sides of the building, in order to undo the connection bolts holding the receiving members 252 to the upper 222 and lower 220 beam assemblies. Before detaching the receiving members 252, the hooks of the crane 256 may be connected to the handrail assemblies 250 in order to lift the apparatus away to safety rather than letting it fall to the ground.

It should be noted that once the floor and roof assembly has been fixed in place on top of the lower storey 214, it is safe for workmen to begin work on the upper storey 216 due to the fact that the upper storey has a floor in place to prevent debris falling on those working below. As soon as the roof truss assembly 218 has been fixed in position, roofing can be laid to provide cover for the upper storey, which allows work to start on the upper storey of the building.

Once the timber frame structure has been completed, scaffolding may be erected in order to build external cladding masonry for the structure, and to fit external components such as guttering. Due to the fact that the building structure has been completed prior to the scaffolding being erected, the scaffolding is in use for a much reduced length of time in comparison with standard building techniques.

When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilized for realizing the invention in diverse forms thereof. 

1. A timber frame structure for a building, comprising: elongate base members extending along lines of respective walls of the building; corner posts extending upwardly from the base members at intersections of respective walls; elongate head members extending between the corner posts at upper end parts thereof; and a plurality of wall panels extending between the head and base members to provide walls for the structure.
 2. A structure according to claim 1 wherein at least some of the wall panels are able to overlap one another in the direction lengthwise of the head and base members, to accommodate changes in the distance between upwardly extending edges of the panels which are remote from one another.
 3. A structure according to claim 2 wherein each wall panel comprises spaced elements of timber which are upright in use and which extend between the head and base members, and a board material connected to the upright members on one side thereof to provide a wall surface between the head and base members, the board material having upper and lower portions which extend to cover, at least partially, corresponding side surfaces of the head and base members respectively.
 4. A structure according to claim 2 wherein a panel includes a board portion which extends beyond an upright element of the panel, for overlapping with the upright edge of an adjacent panel disposed with its board material on the opposite side of the head and base members.
 5. A structure according to claim 1 wherein each head member comprises at least one I-beam, oriented with its chords spaced vertically above one another and its web extending substantially vertically therebetween.
 6. A structure according to claim 5 wherein the lower chord of the head member forms a lintel where door or window openings are provided in the wall.
 7. A structure according to claim 5 wherein a head member comprises two said I-beams disposed one on top of the other in the same orientation as one another.
 8. A method of constructing a timber frame structure for a building, comprising: providing elongate base members along the lines of walls of the building; providing corner posts extending upwardly from the base members at intersections of the respective walls; providing elongate head members extending between the corner posts at upper end parts thereof, above the base members; and providing a plurality of wall panels extending between the head and base members to form walls for the structure.
 9. A method according to claim 8 further comprising adjusting adjacent wall panels in respect of the distance by which they overlap one another in the direction lengthwise of the head and base members, to provide a required length in said direction between edges of the panels which are remote from one another.
 10. A method according to claim 8 comprising assembling head members for a storey of the building into a unit which forms at least part of a ceiling structure for that storey and a floor structure for a further superposed storey, and fitting the assembly to the corner posts of the first said storey as a unit.
 11. A method for constructing a timber-framed building including the steps of: erecting a wall structure of a lower storey of the building; constructing a floor assembly, and assembling a roof truss assembly on top of the floor assembly; releasably connecting the roof truss assembly to the floor assembly using releasable connecting means; placing the connected floor and roof assembly on top of the wall structure of the lower storey; disconnecting the roof truss assembly from the floor assembly and removing the roof truss assembly from the floor assembly; constructing a wall structure of an upper storey on top of the floor assembly; and placing the roof truss assembly on top of the wall structure of the upper storey.
 12. A method according to claim 11, wherein the releasable connecting means comprises a number of connecting assemblies, each comprising a connecting member and a receiving member with which the connecting member is releasably engageable; the connecting member being provided on one of the roof truss assembly and the floor assembly and the receiving member on the other thereof, the connecting member and receiving member engaging and disengaging with one another by relative vertical movement between the roof truss assembly and the floor assembly.
 13. A method according to claim 11, further including providing a guard structure on a part of the releasable connecting means engaging the floor assembly.
 14. A method according to claim 13, including displacing the guard structure relative to the connecting assemblies of the releasable connecting means, between a first position in which the guard structure is positioned relative to the or each connecting assembly so as to enable the roof structure to be connected and disconnected from the floor assembly, and a second position in which it is effective to guard against falls from the upper storey.
 15. A method according to claim 11, further including storing materials for use in the construction of the wall structure of the upper storey on the floor assembly prior to assembling the roof truss structure on top of the floor assembly, so that when the roof truss structure is disconnected from the floor assembly, the materials are disposed on the floor of the upper storey for use in the construction of the wall structure.
 16. A method according to claim 15, further including providing a plurality of spaced parallel joist members between opposite beams of the upper beam assembly, and laying a floor over the joist members, in construction of the floor assembly.
 17. A releasable connecting means for connecting a roof truss assembly to a floor assembly in the method of claim 11, including a number of connecting assemblies, each of which comprises a connecting member and a receiving member, each connectable to the roof truss assembly and floor assembly respectively.
 18. A releasable connecting means according to claim 17, wherein the receiving member has an opening within it, with which at least a part of the connection member is engageable, and the or each connecting assembly further includes a fastening means for holding the connection member in engagement with the receiving member.
 19. A releasable connecting means according to claim 17, further including a guard structure which is provided on a part of the releasable connecting means engaging the floor assembly.
 20. A releasable connecting means according to claim 19, wherein the guard structure is displaceable relative to the connecting assemblies, between a first position in which the guard structure is positioned relative to the or each connecting assembly so as to enable the roof structure to be connected and disconnected from the floor assembly, and a second position in which it is effective to guard against falls from the upper storey.
 21. A releasable connecting means according to claim 20 wherein the guard structure is pivotable relative to the or each connecting assembly comprises pivoting the guard structure between the first position and second position.
 22. A releasable connecting means according to claim 19 wherein the guard structure is extendable lengthwise. 